MFC 333416: Report TRAP_BRKPT for breakpoint traps on sparc64.

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r319873:
Move struct syscall_args syscall arguments parameters container into
struct thread.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Use our nitems() macro when param.h is available.

Replacements specific to arm, mips, pc98, powerpc and sparc64.

Discussed in: freebsd-current

Do not hold the process around the vm_fault() call from the trap()s.
The only operation which is prevented by the hold is the kernel stack
swapout for the faulted thread, which should be fine to allow.

Remove useless checks for NULL curproc or curproc->p_vmspace from the
trap_pfault() wrappers on x86 and powerpc.

Reviewed by: alc (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

Generalised support for copy-on-write structures shared by threads.

Thread credentials are maintained as follows: each thread has a pointer to
creds and a reference on them. The pointer is compared with proc's creds on
userspace<->kernel boundary and updated if needed.

This patch introduces a counter which can be compared instead, so that more
structures can use this scheme without adding more comparisons on the boundary.

userret() already checks for td_locks when INVARIANTS is enabled, so
there is no need to check if Giant is acquired after it.

Reviewed by: kib
MFC after: 1 week

Remove checks that are redundant due to tf_type being unsigned.

MFC after: 3 days

Fix panic on kernel traps having a mapping in trap_sig b0rked in r206086.
Repored by: David E. Cross

MFC after: 3 days

Inline the syscallenter() and syscallret(). This reduces the time measured
by the syscall entry speed microbenchmarks by ~10% on amd64.

Submitted by: jhb
Approved by: re (bz)
MFC after: 2 weeks

Remove the advertising clause from the UCB license according to the
July 22, 1999 addendum.

Fix typos - remove duplicate "the".

PR: bin/154928
Submitted by: Eitan Adler <lists at eitanadler.com>
MFC after: 3 days

Remove unused KTRACE includes.

Reorganize syscall entry and leave handling.

Extend struct sysvec with three new elements:
sv_fetch_syscall_args - the method to fetch syscall arguments from
usermode into struct syscall_args. The structure is machine-depended
(this might be reconsidered after all architectures are converted).
sv_set_syscall_retval - the method to set a return value for usermode
from the syscall. It is a generalization of
cpu_set_syscall_retval(9) to allow ABIs to override the way to set a
return value.
sv_syscallnames - the table of syscall names.

Use sv_set_syscall_retval in kern_sigsuspend() instead of hardcoding
the call to cpu_set_syscall_retval().

The new functions syscallenter(9) and syscallret(9) are provided that
use sv_*syscall* pointers and contain the common repeated code from
the syscall() implementations for the architecture-specific syscall
trap handlers.

Syscallenter() fetches arguments, calls syscall implementation from
ABI sysent table, and set up return frame. The end of syscall
bookkeeping is done by syscallret().

Take advantage of single place for MI syscall handling code and
implement ptrace_lwpinfo pl_flags PL_FLAG_SCE, PL_FLAG_SCX and
PL_FLAG_EXEC. The SCE and SCX flags notify the debugger that the
thread is stopped at syscall entry or return point respectively. The
EXEC flag augments SCX and notifies debugger that the process address
space was changed by one of exec(2)-family syscalls.

The i386, amd64, sparc64, sun4v, powerpc and ia64 syscall()s are
changed to use syscallenter()/syscallret(). MIPS and arm are not
converted and use the mostly unchanged syscall() implementation.

Reviewed by: jhb, marcel, marius, nwhitehorn, stas
Tested by: marcel (ia64), marius (sparc64), nwhitehorn (powerpc),
stas (mips)
MFC after: 1 month

Unlike the sun4v variant, the sun4u version of SUNW,set-trap-table
actually only takes one argument.

- Try do deal gracefully with correctable ECC errors.
- Improve the reporting of unhandled kernel and user traps.

Some machines can not only consist of CPUs running at different speeds
but also of different types, f.e. Sun Fire V890 can be equipped with a
mix of UltraSPARC IV and IV+ CPUs, requiring different MMU initialization
and different workarounds for model specific errata. Therefore move the
CPU implementation number from a global variable to the per-CPU data.
Functions which are called before the latter is available are passed the
implementation number as a parameter now.

Merge r202882 from amd64/i386:

For PT_TO_SCE stop that stops the ptraced process upon syscall entry,
syscall arguments are collected before ptracestop() is called. As a
consequence, debugger cannot modify syscall or its arguments.

In syscall(), reread syscall number and arguments after ptracestop(),
if debugger modified anything in the process environment. Since procfs
stopevent requires number of syscall arguments in p_xstat, this cannot
be solved by moving stop/trace point before argument fetching.

Move the code to read arguments into separate function
fetch_syscall_args() to avoid code duplication. Note that ktrace point
for modified syscall is intentionally recorded twice, once with original
arguments, and second time with the arguments set by debugger.

PT_TO_SCX stop is executed after cpu_syscall_set_retval() already.

Reviewed by: kib

Add <machine/pcb.h> missed in r199135.

Simplify the invocation of vm_fault(). Specifically, eliminate the flag
VM_FAULT_DIRTY. The information provided by this flag can be trivially
inferred by vm_fault().

Discussed with: kib

Extract the code that records syscall results in the frame into MD
function cpu_set_syscall_retval().

Suggested by: marcel
Reviewed by: marcel, davidxu
PowerPC, ARM, ia64 changes: marcel
Sparc64 tested and reviewed by: marius, also sunv reviewed
MIPS tested by: gonzo
MFC after: 1 month

- There's no need to wrap kdb_active and kdb_trap() in #ifdef KDB as
they're always available.
- Remove unused variable. [1]
- Add a missing const.
- Sort includes.

Submitted by: Christoph Mallon [1]

Modularize the Open Firmware client interface to allow run-time switching
of OFW access semantics, in order to allow future support for real-mode
OF access and flattened device frees. OF client interface modules are
implemented using KOBJ, in a similar way to the PPC PMAP modules.

Because we need Open Firmware to be available before mutexes can be used on
sparc64, changes are also included to allow KOBJ to be used very early in
the boot process by only using the mutex once we know it has been initialized.

Reviewed by: marius, grehan

Use the PROM provided SUNW,set-trap-table to take over the trap
table. This is required in order to set obp-control-relinquished
within the PROM, allowing to safely read the OFW translations node.
Without this, f.e. a `ofwdump -ap` triggers a fatal reset error or
worse things on machines based on USIII and beyond.
In theory this should allow to remove touching %tba in cpu_setregs(),
in practice we seem to currently face a chicken and egg problem when
doing so however.

There's a race in kmem(4) between checking whether a page is resident
in the kernel and copying it out, causing a panic when faulting on a
nofault entry. Handle this case gracefully by letting the kernel copy
functions return EFAULT instead. As such this change addresses the
same problem as r154721 does for i386.

MFC after: 3 days

MFamd64: r133413

In syscall, always make a copy of parameters from trapframe, this
becauses some syscalls using set_mcontext can sneakily change
parameters and later when those syscalls references parameters,
they will wrongly use register values in mcontext_t.

PR: 72998
MFC after: 3 days

cosmetic changes and style fixes

Remove kernel support for M:N threading.

While the KSE project was quite successful in bringing threading to
FreeBSD, the M:N approach taken by the kse library was never developed
to its full potential. Backwards compatibility will be provided via
libmap.conf for dynamically linked binaries and static binaries will
be broken.

Add a new 'why' argument to kdb_enter(), and a set of constants to use
for that argument. This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.

Assign approximate why values to all current consumers of the
kdb_enter() interface.

Rework the PCPU_* (MD) interface:
- Rename PCPU_LAZY_INC into PCPU_INC
- Add the PCPU_ADD interface which just does an add on the pcpu member
given a specific value.

Note that for most architectures PCPU_INC and PCPU_ADD are not safe.
This is a point that needs some discussions/work in the next days.

Reviewed by: alc, bde
Approved by: jeff (mentor)

Over NFS, an open() call could result in multiple over-the-wire
GETATTRs being generated - one from lookup()/namei() and the other
from nfs_open() (for cto consistency). This change eliminates the
GETATTR in nfs_open() if an otw GETATTR was done from the namei()
path. Instead of extending the vop interface, we timestamp each attr
load, and use this to detect whether a GETATTR was done from namei()
for this syscall. Introduces a thread-local variable that counts the
syscalls made by the thread and uses <pid, tid, thread syscalls> as
the attrload timestamp. Thanks to jhb@ and peter@ for a discussion on
thread state that could be used as the timestamp with minimal overhead.

Make KSE a kernel option, turned on by default in all GENERIC
kernel configs except sun4v (which doesn't process signals properly
with KSE).

Reviewed by: davidxu@

Retire SYF_ARGMASK and remove both SYF_MPSAFE and SYF_ARGMASK. sy_narg is
now back to just being an argument count.

Now that all system calls are MPSAFE, retire the SYF_MPSAFE flag used to
mark system calls as being MPSAFE:
- Stop conditionally acquiring Giant around system call invocations.
- Remove all of the 'M' prefixes from the master system call files.
- Remove support for the 'M' prefix from the script that generates the
syscall-related files from the master system call files.
- Don't explicitly set SYF_MPSAFE when registering nfssvc.

Unify the checking for lock misbehavior in the various syscall()
implementations and adjust some of the checks while I'm here:
- Add a new check to make sure we don't return from a syscall in a critical
section.
- Add a new explicit check before userret() to make sure we don't return
with any locks held. The advantage here is that we can include the
syscall number and name in syscall() whereas that info is not available
in userret().
- Drop the mtx_assert()'s of sched_lock and Giant. They are replaced by
the more general checks just added.

MFC after: 2 weeks

Since DELAY() was moved, most <machine/clock.h> #includes have been
unnecessary.

For USIII CPUs the type of the trap caused by peeking/poking non-existent
PCI devices apparently was changed from a special deferred trap with TPC
pointing to the membar #Sync following the failing load/store instruction
to a precise trap with TPC pointing to the failing load/store instruction.
Thus remove the check the check whether TPC points to a membar #Sync in
case of a data access trap as it's off-by-one for USIII CPUs and it should
be sufficient to check whether the trap happend while in fasword*() to
properly detect traps caused by peeking/poking. This also corresponds to
what other OSs do. Note that also only the USIIi manual suggests to check
the TPC for such traps while the USII one doesn't (in the public USIII
manual device peeking/poking isn't mentioned at all).

- s,tramoline,trampoline, in a comment.
- Use FBSDID in trap.c
- Make the global trap_sig[] static as it's not used outside of trap.c.
- In sendsig() remove an unused variable.
- In trap() sync with the other archs; for fast data access MMU miss and
data access protection traps set ksi_addr to the SFAR reg which contains
the faulting address and otherwise to the TPC reg. Generally the TCP reg
contains the address of the instruction that caused the exception, except
for fast instruction access traps (and some others; more refinement may
be needed here) it also contains the faulting address.
Previously sendsig() always set si_addr to the SFAR reg which is wrong
for most traps.
- In sendsig() add support for FreeBSD old-style signals.

These changes are inspired by kmacy's sun4v changes and allow libsigsegv
to build on FreeBSD/sparc64, but it doesn't pass all checks and tests it
actually should, yet.

MFC after: 5 days

Fix a c/p error.

Obtained from: The TrustedBSD Project
Approved by: rwatson (mentor)

Add system call auditing support for sparc64.

Submitted by: brueffer
Obtained from: TrustedBSD Project

Simplify system time accounting for profiling.

Rename struct thread's td_sticks to td_pticks, we will need the
other name for more appropriately named use shortly. Reduce it
from uint64_t to u_int.

Clear td_pticks whenever we enter the kernel instead of recording
its value as reference for userret(). Use the absolute value of
td->pticks in userret() and eliminate third argument.

Fix compiling.

1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64

Use PCPU_LAZY_INC() for cnt.v_{intr,trap,syscalls} rather than atomic
operations in some places and simple non-per CPU math in others.

Don't include sys/user.h merely for its side-effect of recursively
including other headers.

Remove an unneeded argument..
The removed argument could trivially be derived from the remaining one.
That in turn should be the same as curthread, but it is possible that curthread could be expensive to derive on some syste,s so leave it as an argument.
Having both proc and thread as an argumen tjust gives an opportunity for
them to get out sync.

MFC after: 3 days

Remove sched_free_thread() which was only used
in diagnostics. It has outlived its usefulness and has started
causing panics for people who turn on DIAGNOSTIC, in what is otherwise
good code.

MFC after: 2 days

Update for the KDB framework:
o Make debugging code conditional upon KDB instead of DDB.
o Call kdb_enter() instead of Debugger().
o Remove implementation of Debugger().
o Check kdb_active instead of db_active.
o Call kdb_trap() according to the new world order.

Fix a bug in the data access error recorvery. Before re-enabling the data
cache after a data access error we must discard all cache lines. When
disabled existing cache lines are not invalidated by stores to memory, so
we risk reading stale data that was cached before the data access error if
we don't flush them. This is especially fatal when the memory involved
is the active part of the kernel or user stack. For good measure we also
flush the instruction cache.

This fixes random crashes when the X server probes the PCI bus through
/dev/pci.

Add an 'include' directive to pull in <sys/ptrace.h>.

Implement preliminary support for the PT_SYSCALL command to ptrace(2).

Prefer new location of pci include files (which have only been in the
tree for two or more years now), except in a few places where there's
code to be compatible with older versions of FreeBSD.

remove unnecessary comment. We do what the comments says we need to.

add support for peeking at pci busses on UltraSparc systems. This prevents
data access errors when trying to read/write to non-existant PCI devices.

fix the psycho bridge to use peek for probing devices. This no longer
fakes it if the OFW node doesn't exist (and the reg == 0).

Reviewed by: jake, tmm

Rename P_THREADED to P_SA. P_SA means a process is using scheduler
activations.

Forgot to update string and signal tables when some of the trap types
changed.

Range check the syscall number before looking it up in the syscallnames[]
array.

Submitted by: pho

Remove single threading detecting code, these code really should be
replaced by thread_user_enter(), but current we don't want to enable
this in trap.

Use the proc lock to protect p_singlethread and a P_WEXIT test. This
fixes a couple of potential KSE panics on non-i386 arch's that weren't
holding the proc lock when calling thread_exit().

- Change trapsignal() to accept a thread and not a proc.
- Change all consumers to pass in a thread.

Right now this does not cause any functional changes but it will be important
later when signals can be delivered to specific threads.

Replace calls to WITNESS_SLEEP() and witness_list() with equivalent calls
to WITNESS_WARN().

Change the process flags P_KSES to be P_THREADED.
This is just a cosmetic change but I've been meaning to do it for about a year.

cat KSE > /dev/null

- Move ke_sticks, ke_iticks, ke_uticks, ke_uu, ke_su, and ke_iu back into
the proc. These counters are only examined through calcru.

Submitted by: davidxu
Tested on: x86, alpha, UP/SMP

Reversion of commit by Davidxu plus fixes since applied.

I'm not convinced there is anything major wrong with the patch but
them's the rules..

I am using my "David's mentor" hat to revert this as he's
offline for a while.

Move UPCALL related data structure out of kse, introduce a new
data structure called kse_upcall to manage UPCALL. All KSE binding
and loaning code are gone.

A thread owns an upcall can collect all completed syscall contexts in
its ksegrp, turn itself into UPCALL mode, and takes those contexts back
to userland. Any thread without upcall structure has to export their
contexts and exit at user boundary.

Any thread running in user mode owns an upcall structure, when it enters
kernel, if the kse mailbox's current thread pointer is not NULL, then
when the thread is blocked in kernel, a new UPCALL thread is created and
the upcall structure is transfered to the new UPCALL thread. if the kse
mailbox's current thread pointer is NULL, then when a thread is blocked
in kernel, no UPCALL thread will be created.

Each upcall always has an owner thread. Userland can remove an upcall by
calling kse_exit, when all upcalls in ksegrp are removed, the group is
atomatically shutdown. An upcall owner thread also exits when process is
in exiting state. when an owner thread exits, the upcall it owns is also
removed.

KSE is a pure scheduler entity. it represents a virtual cpu. when a thread
is running, it always has a KSE associated with it. scheduler is free to
assign a KSE to thread according thread priority, if thread priority is changed,
KSE can be moved from one thread to another.

When a ksegrp is created, there is always N KSEs created in the group. the
N is the number of physical cpu in the current system. This makes it is
possible that even an userland UTS is single CPU safe, threads in kernel still
can execute on different cpu in parallel. Userland calls kse_create to add more
upcall structures into ksegrp to increase concurrent in userland itself, kernel
is not restricted by number of upcalls userland provides.

The code hasn't been tested under SMP by author due to lack of hardware.

Reviewed by: julian

Allow deprecated or unimplemented system call vectors to deliver SIGSYS,
as suggested by the sparc v9 ABI.

Greatly improve readability of trap() by using a table to convert between
trap types and signals to send. Rearrange KASSERTs to better handle faults
early before curthread is setup, or in the case that it gets corrupted or
set to 0.

Extract out KSE specific code from machine specific code
so that there is ony one copy of it. Fix that one copy
so that KSEs with no mailbox in a KSE program are not a cause
of page faults (this can legitmatly happen).

Submitted by: (parts) davidxu

- Expand struct trapframe to 256 bytes, make all fields fixed width and the
same size. Add some fields that previously overlapped with something else
or were missing.
- Make struct regs and struct mcontext (minus floating point) the same as
struct trapframe so converting between them is easy (null).
- Add space for saving floating point state to struct mcontext. This requires
that it be 64 byte aligned.
- Add assertions that none of these structures change size, as they are part
of the ABI.
- Remove some dead code in sendsig().
- Save and restore %gsr in struct trapframe. Remember to restore %fsr.
- Add some comments to exception.S.

Fix standard kse breakge of non-x86 platforms. sigh.

Pointy hat to: kse

Demark sections of code that need special fault handling with labels.
Check if the trapped pc is inside of the demarked sections to implement
fault recovery for copyin etc, instead of pcb_onfault. Handle recovery
from data access exceptions as well as page faults.

Inspired by: bde's sys.dif

Add additional cred_free_thread() calls that I had missed the first time.

Pointed out by: jhb

thread_exit() requires PROC_LOCK to be held, so lock it.

Fix reverse ordering of locks. add a comment about locks on some platforms.

Submitted by: jhb@freebsd.org

Part 1 of KSE-III

The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)

NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..

Remove unused diagnostic function cread_free_thread().

Approved by: alfred

Add code to drop to ddb when a process gets a fatal signal that usually
suggests kernel bugs (4, 10, 11). Add a sysctl debug.debugger_on_signal
which turns this on and off, default off.

Remove code from trap which is handled in userland now.

- Fixup / remove obsolete comments.
- ktrace no longer requires Giant so do ktrace syscall events before and
after acquiring and releasing Giant, respectively.
- For i386, ia32 syscalls on ia64, powerpc, and sparc64, get rid of the
goto bad hack and instead use the model on ia64 and alpha were we
skip the actual syscall invocation if error != 0. This fixes a bug
where if we the copyin() of the arguments failed for a syscall that
was not marked MP safe, we would try to release Giant when we had
not acquired it.

Merge the code in pv.c into pmap.c directly. Place all page mappings onto
the pv lists in the vm_page, even unmanaged kernel mappings. This is so
that the virtual cachability of these mappings can be tracked when a page
is mapped to more than one virtual address. All virtually cachable
mappings of a physical page must have the same virtual colour, or illegal
alises can be created in the data cache. This is a bit tricky because we
still have to recognize managed and unmanaged mappings, even though they
are all on the pv lists.

Banish "priviledged" from kernel source.

MFi386 1.222. Remove vm_map_growstack and acquisition and release of Giant
from trap_pfault.

Forgot these files in previous commit to frame.h. Also add needed include
of machine/emul.h.

Add missing includes for the KTRACE case.

Fix syscall ktraceing.

Make this compile without options DDB; use intr_disable() instead of
fiddling with PSTATE_IE manually.

Remove references to vm_zone.h and switch over to the new uma API.

Reviewed by: jake

Change the way we ensure td_ucred is NULL if DIAGNOSTIC is defined.
Instead of caching the ucred reference, just go ahead and eat the
decerement and increment of the refcount. Now that Giant is pushed down
into crfree(), we no longer have to get Giant in the common case. In the
case when we are actually free'ing the ucred, we would normally free it on
the next kernel entry, so the cost there is not new, just in a different
place. This also removse td_cache_ucred from struct thread. This is
still only done #ifdef DIAGNOSTIC.

Tested on: i386, alpha

Implement delivery of tlb shootdown ipis. This is currently more fine grained
than the other implementations; we have complete control over the tlb, so we
only demap specific pages. We take advantage of the ranged tlb flush api
to send one ipi for a range of pages, and due to the pm_active optimization
we rarely send ipis for demaps from user pmaps.

Remove now unused routines to load the tlb; this is only done once outside
of the tlb fault handlers.
Minor cleanups to the smp startup code.

This boots multi user with both cpus active on a dual ultra 60 and on a
dual ultra 2.

- Move a comment from being on the same line as a #ifdef to the line
following it. This should have gone in the previous commit, but
misviewed Bruce's patch.

Requested by: bde

- Fix panic() message and a couple style nits that snuck in from the
recent diagnostics commit (rev. 1.84).

Convert pmap.pm_context to an array of contexts indexed by cpuid. This
doesn't make sense for SMP right now, but it is a means to an end.

Add some DIAGNOSTIC code.
While in userland, keep the thread's ucred reference in a shadow
field so that the usual place to store it is NULL.
If DIAGNOSTIC is not set, the thread ucred is kept valid until the next
kernel entry, at which time it is checked against the process cred
and possibly corrected. Produces a BIG speedup in
kernels with INVARIANTS set. (A previous commit corrected it
for the non INVARIANTS case already)

Reviewed by: dillon@freebsd.org

Catch up with i386 change I forgot to commit.

Add a panic stack, which is used as a known good stack when there is
something wrong with the kernel stack.
Add code to check the kernel stack pointer in various important places
and try hard not to go down in flames if its wrong.

Make these compile.

1. Adapt to new trap types.
2. Make trap_pfault more like it is on other architectures.
3. Fix a bug in syscall() which caused system calls with more than
six arguments that are called through the wild card syscall to
have their arguments scrambled. This affected mmap due to the
(bogus) wrapper in libc.

Submitted by: tmm (3)

1. Split fp.h into fp.h and fsr.h so that the latter can be included
in asm files.
2. Temporarily cause subnormal operands in floating point operations
to be treated as zeros so that comlpetion of the operation does not
need to be emulated.
3. Catch fp_exception_other and correctly skip over the unfinished
instruction, but basically ignore them. Emulating the instruction
is not yet supported.
4. Zero td_retval[1] as well in syscall().

Submitted by: tmm (2, 3)

Add code to emulate unimplemented (non-fp) instructions and to fixup
unaligned accesses, and instr.h, which contrains definitions for the
sparc64 instruction set (partly from NetBSD).
Make use of some definitions from instr.h in db_disasm.c.

Handle instruction access mmu miss faults in kernel mode. These can only
be generated by non-preloaded klds.

Add a per-thread ucred reference for syscalls and synchronous traps from
userland. The per thread ucred reference is immutable and thus needs no
locks to be read. However, until all the proc locking associated with
writes to p_ucred are completed, it is still not safe to use the per-thread
reference.

Tested on: x86 (SMP), alpha, sparc64

Add support for physical address hardware watchpoints.

Add inthand_add() and inthand_remove() for use by the MD bus code and
some glue code.

Split the low level trap code into trap, interrupt and syscall, its
easier and hopefully this code is done changing radically.

Don't use the mmu tlb register to address the kernel page table, nor
the 8k pointer register. The hardware will do some of the page table
lookup by storing the the base address in an internal register and
calculating the address of the tte in the table. However it is limited
to a 1 meg tsb, which only maps 512 megs. The kernel page table only
has one level, so its easy to just do it by hand, which has the advantage
of supporting abitrary amounts of kvm and only costs a few more instructions.

Increase kvm to 1 gig now that its easy to do so and so we don't waste
most of a 4 meg page.

Fix some traces. Fix more proc locking.

Call tsb_stte_promote if we get a soft fault on a mapping in the upper
levels of the tsb. If there is an invalid or unreferenced mapping
in the primary tsb, it will be replaced.

Immediately fail for faults occuring in {f,s}uswintr.

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

Implement pv_bit_count which is used by pmap_ts_referenced.

Remove the modified tte bit and add a softwrite bit. Mappings are only
writeable if they have been written to, thus in general modify just
duplicates the write bit. The softwrite bit makes it easier to distinguish
mappings which should be writeable but are not yet modified.

Move the exec bit down one, it was being sign extended when used as an
immediate operand.

Use the lock bit to mean tsb page and remove the tsb bit. These are the
only form of locked (tsb) entries we support and we need to conserve bits
where possible.

Implement pmap_copy_page and pmap_is_modified and friends.

Detect mappings that are being being upgraded from read-only to read-write
due to copy-on-write and update the write bit appropriately.

Make trap_mmu_fault do the right thing for protection faults, which is
necessary to implement copy on write correctly. Also handle a bunch
more userland trap types and add ktr traces.

Remove the MPSAFE keyword from the parser for syscalls.master.
Instead introduce the [M] prefix to existing keywords. e.g.
MSTD is the MP SAFE version of STD. This is prepatory for a
massive Giant lock pushdown. The old MPSAFE keyword made
syscalls.master too messy.

Begin comments MP-Safe procedures with the comment:
/*
* MPSAFE
*/
This comments means that the procedure may be called without
Giant held (The procedure itself may still need to obtain
Giant temporarily to do its thing).

sv_prepsyscall() is now MP SAFE and assumed to be MP SAFE
sv_transtrap() is now MP SAFE and assumed to be MP SAFE

ktrsyscall() and ktrsysret() are now MP SAFE (Giant Pushdown)
trapsignal() is now MP SAFE (Giant Pushdown)

Places which used to do the if (mtx_owned(&Giant)) mtx_unlock(&Giant)
test in syscall[2]() in */*/trap.c now do not. Instead they
explicitly unlock Giant if they previously obtained it, and then
assert that it is no longer held to catch broken system calls.

Rebuild syscall tables.

Add a system call trap type and syscall() call request handler.
Also add support for hardware watch point traps.

Submitted by: tmm

Don't needlessly duplicate what's basically the same copyright.

- Close races with signals and other AST's being triggered while we are in
the process of exiting the kernel. The ast() function now loops as long
as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with
preemption disabled so that any further AST's that arrive via an
interrupt will be delayed until the low-level MD code returns to user
mode.
- Use u_int's to store the tick counts for profiling purposes so that we
do not need sched_lock just to read p_sticks. This also closes a
problem where the call to addupc_task() could screw up the arithmetic
due to non-atomic reads of p_sticks.
- Axe need_proftick(), aston(), astoff(), astpending(), need_resched(),
clear_resched(), and resched_wanted() in favor of direct bit operations
on p_sflag.
- Fix up locking with sched_lock some. In addupc_intr(), use sched_lock
to ensure pr_addr and pr_ticks are updated atomically with setting
PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing
PS_OWEUPC. We also do not grab the lock just to test a flag.
- Simplify the handling of Giant in ast() slightly.

Reviewed by: bde (mostly)

Use the macro for getting the trap type from the trapframe.
Only set sticks (and acquire sched_lock) on entry from user mode.
Add handlers for all kinds of mmu misses, and for interrupts from
user mode.
Acquire Giant before calling into the vm system so this runs with
invariants.
Try to get the restrictions for page faults on user memory from
kernel mode right.
Only set pcb_onfault and return to the alternate return code if
this is actually a fault on user memory from kernel mode.

The author isn't a [UC] Regents. Correct the copyright language.

Add page fault and high level tsb miss handlers.

Add floating point context switching code for sparc64.

Reviewed by: jake

Flesh out the sparc64 port considerably. This contains:
- mostly complete kernel pmap support, and tested but currently turned
off userland pmap support
- low level assembly language trap, context switching and support code
- fully implemented atomic.h and supporting cpufunc.h
- some support for kernel debugging with ddb
- various header tweaks and filling out of machine dependent structures

Add skeleton machine dependent headers and c files for a port of freebsd
to a new architecture. This is the base of the sparc64 port, but contains
limited machine dependent code, and can be used a base for ports. Included
are:
- standard machine dependent headers, tweaked for a 64 bit, big endian
architecture, including empty versions of all the machine dependent
structures
- a machine independent atomic.h, which can be used until a port has
support for interrupts and the operations really need to be atomic
- stub versions of all the machine dependent functions, which panic
when called and print out the name of the function that needs to
be implemented. functions which are normally in assembly files are
not included, but this should reduce the number of different undefined
references on the first few compiles from hundreds to 5 or 6
Given minimal startup code and console support it should be trivial to
make this compile and run the first few sysinits on almost any architecture.

Requested by: alfred, imp, jhb